1. Field of the Invention
This invention relates to a manual relief gas vent which can be placed in drums to control the pressure in the drum.
2. Description of the Previously Published Art
Various chemical materials have been stored in sealed drums. Some of these materials will produce a gas. After a period of time a gas pressure will build up and a problem develops as to how to safely vent the gas, especially when it is an explosive gas such as hydrogen. For example, when Raney nickel is stored in a sealed drum, there is a tendency for hydrogen gas to be generated. If the sealed drum is not vented, the gas pressure will build up and it can cause the drum lid to be blown off. When the drum is opened for use, it is necessary to carefully open the drum band and slowly pry up the lid to relieve any gas pressure which may exist inside. This can be a problem since if there is alot of gas pressure the lid can be blown off causing burns or projectile injury.
One solution to the problem is to use an automatic relief valve which is spring loaded. It could be set to vent the drum whenever the pressure was above a certain level such as 3 psig. There is an environmental control problem with these valves because there is no way to control the gas coming off. If there are many drums in an unvented storage room on a hot day, the drums will all generate alot of gas which the valves will automatically vent to the room. There will be no way to prevent the gas from accumulating in the room.
Gas vents have been placed in drums in the past, but these vents extend vertically to some extent such that they extend above the rim of the drum when they are inserted into the bung hole of the drum lid. When the valves extend above the drums, it is not possible to stack the drums one on top of the other.
3. Objects of the Invention
It is an object of this invention to have a valve assembly for a drum which is compact and which fits in the bung hole of a drum so that it does not extend above the height of the drum rim.
It is a further object of this invention to have a manually operated gas relief valve which can be safely operated to vent even explosive gas from a sealed drum, while providing a positive seal when such venting is prohibited.
It is a further object of this invention to have a valve assembly for a drum where the valve outlet is protectively positioned in a reservoir within the valve assembly.
It is a further object of this invention to have a valve assembly where the valve outlet discharges into a reservoir which can be filled with water or other inert fluid to detect the flow of gas from the outlet as bubbles in the reservoir.
It is a further object of this invention to have a valve assembly that provides and identifies a positive neutral drum condition exists prior to drum opening without concern of plugging or other vent failure.
These and further objects will become apparent as the description of the invention proceeds.